Lunyu VII. 19. (169)

Confucius's description of his own character, as being simply a cheerful, earnest learner.
1. The Duke of Sheh asked Tsze-lû about Confucius, and Tsze-lû did not answer him.
2. The Master said, "Why did you not say to him, – He is simply a man, who in his eager pursuit of knowledge forgets his food, who in the joy of its attainment forgets his sorrows, and who does not perceive that old age is coming on?"

Legge VII.18.

The Governor of She asked Tzu-lu about Confucius. Tzu-lu did not answer. The Master said, 'Why did you not simply say something to this effect: he is the sort of man who forgets to eat when he tries to solve a problem that has been driving him to distraction, who is so full of joy that he forgets his worries and who does not notice the onset of old age?'